Synthetic resin seamless tetrahedron

ABSTRACT

An improved container of tetrahedral shape comprising a seamless tube of thermoplastic material having the opposite ends thereof sealed in straight lines in crosswise directions relative to one another; and the method of cutting, forming, expanding, filling and sealing such tubular material with novel material handling techniques to provide filled containers of tetrahedral shape.

United States Patent 1191 Izumi 1 1 Jan. 16, 1973 l SYNTHETIC RESINSEAMLESS I Reierences Cited TETRAHEDRON UNITED STATES PATENTS Inventorsh'njim 1 3,236,021 2/1966 Wagner ct al. .53 29 chome, UraWa-Shl Japan2,962,843 12/1960 HOBIZCICI al. ..53/28 x 3,557,526 l/l97l Hartmann..53/183 [22] 1970 3,543,466 1/1970 Forsberg ..s3/3s4 x [21] Appl. No.:100,568

Primary Examiner-Theron E. Condon Assistant ExaminerEugene F. Desmond[30] Foreign Application Priority Data Attorney Toren & McGeady Dec. 22,1969 Japan ..44/l03598 Dec. 29, 1969 Japan ..44/489 [571 ABSTRACT Animproved container of tetrahedral shape compris- [52] US. Cl. .53/29,53/183, 53/384, ing a seamless tube of thermoplastic material having53/386 the opposite ends thereof sealed in straight lines in [51] Int.Cl ..B65b 9/10, B65b 43/30 crosswise directions relative to one another;and the {58] Field of Search....53/28, 29, 183, 187, 384, 386, method ofcutting, forming, expanding, filling and 53/130 141 sealing such tubularmaterial with novel material handling techniques to provide filledcontainers of tetrahedral shape.

4 Claims, 19 Drawing Figures PATENTEDJAH 16 I973 3.710.541

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o o o 0 o o o o 0 o o o o o 9) 0% I" FIG. I9 I INVENTOR SH/NJIRO IZUM/NY I 7mm? W AT ORN 5 SYNTHETIC RESIN SEAMLESS TETRAHEDRON BACKGROUND OFTHE INVENTION It is already known to use a tetrahedron container formilk and other fluids or small particle solids (powdered or granulatedmaterials). In the conventional tetrahedron container consisting ofpaper or paper laminated with synthetic resin or paper coated with wax,it is necessary to form a longitudinal seam in making it from a tube. Onthis account, the manufacturing process is complicated and moreoverthere is a risk of leakage of the contents from this seam and there is arisk that the sealed opening may be imperfect.

The present invention is directed at eliminating the defects of suchconventional containers and providing a container which is easy tomanufacture and affords excellent seals.

One special feature of the present invention resides in employing aseamless flatly folded tube as the material for the tetraphedron therebyeliminating problems due to the presence of a longitudinal seam.

The second special feature of the present invention resides in that theopening of the subsequently sealed tetrahedral unit makes possiblekeeping it widely opened without aid of the other means by changing thedirection of the folds in such a manner that these folds may just beoverlapped.

Another special feature of the present invention resides in that thefolds of the tube are adapted to be guided in the state in which thesefolds are overlapped by introducing the fold of the tube in the groovescircumferentially provided at the opposite places of the rollsconstituting a portion for pulling out the tube.

SUMMARY OF THE INVENTION The present invention relates to a novelarticle in the form of a tetrahedrally shaped container of thermoplasticmaterial with seals disposed along two edges of crosswise orientation inthe article; and it further relates to an improved method of forming abag from a seamless tube of thermoplastic material, filling and thensealing the bag in producing the tetrahedral article by novel handlingtechniques.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which there are illustrated and described preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is an elevation view of one embodiment of the apparatus;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a detail view illustrating a vacuum holding device of theapparatus of FIG. 1;

FIG. 4 is a plan view of another embodiment of such apparatus;

FIG. 5 is an elevation of the apparatus of FIG. 4;

FIG. 6 is a sectional view of the adhesive holding device employed inthe embodiment of FIG. 4;

FIG. 7 is a sectional elevation depicting the sequential operation ofanother modification of the adhesive holding device;

FIG. 8 is an elevation view, partly in section, showing the holdingdevice of FIG. 6 in the expansion operation;

FIGS. 9 and 10 are plan and elevation views showing the operation of anextendable compass like forming member; FIGS. 11 and 12 are viewssimilar to FIGS. 2 and 1, respectively, in which the vacuum holdingdevice is replaced by an adhesive holding device;

FIG. 13 is a plan view showing the operation of a rotary type ofapparatus;

FIG. 14 is a plan view showing the bag-forming and bag-fillingoperations taking place on separate circular sections of a machine;

FIGS. 15 and 16 are views similar to FIGS. 2 and 1, respectively,showing a moving heat sealing device;

FIG. 17 is an elevation showing these filling steps; and

FIGS. 18 and 19 are a plan view and an elevation view, respectively,showing the method in which all steps of forming, filling, and sealingthe tetrahedron container are performed in a straight line.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, anadsorbing member or a holding device 2 is mounted on a chain 3 movingaround the machine body on sprocket wheels 19 and 20, a chain 9 runsparallel with this body around shafts l2, 12 in the direction of thearrow and in concert with the chain 3 of the body; a cutting bladedevice 7 is mounted on this chain 9, a flatly folded tube 1 of seamlesssynthetic resin thermoplastic material is pulled away from the roll onshaft 10 by the vacuum holding device 2 and is gradually cut off bymeans of the cutting device 7 moving along with tube 1; the rear edge ofthe sealed tube is heat sealed as described hereinafter by means of aheat sealing member 16, the flatly folded tube is expanded by theholding device while the fold of the folded tube is supported by asupport member 17; and then the vacuum in a suction tube 21 is releasedand the holding device 2 is retracted from the expanded article which issupported by the supporting member 17. Now, the tubular article is in anexpanded state with one end open as shown at the left of FIG. 3 and itis moved to an erect position by means of a lever 18, and it is filledwith a fixed quantity of fluid or small particle solids supplied from atube 1 1 beneath a rotating rotary head or tank 4 as shown in FIGS. 1and 2. When this filling up is completed, as shown on the upper part ofFIG. 2, the open end of the plastic container is gradually closed andheat sealed by heat seal plates 15, (see also FIG. 3), fluid or smallsolids are received and sealed in the container which now has the shapeof a tetrahedron. The sealed container is detached from the machine bycontact with a guide 14 and fed onto a conveyor (not illustrated).

The fluid or small solids are received in a tank 4 from a tube 6. Theholding device 2 and the heat seal device 15 are mounted on the chain 3running with a combin'ation of circular and rectilinear motions providedby means of a sprocket wheel 19 and sprocket wheels 20 to facilitate thecutting and sealing of the tubular material. An important benefit ofthis invention is the economical and faster handling resulting from theuse of a preformed seamless synehetic resin tube supplied as a roll offlattened material on the core or shaft whereas conventional systemsinvolve first forming a tube from the material and then making acontinuous longitudinal seam. In the case of seamed containers marketedup to the present, 5,000 to 6,000 pieces per hour are maximum productionrates, while this new method has three important advantages, namely,such high efficiency that production rates of 20,000 to 30,000 piecesper hour are possible, a machine of smaller size serves the purpose andthe economical handling previously mentioned.

In the second embodiment shown in FIGS. 4 to 12, and referring now toFIGS. 4 and 5, a flatly folded seamless tube 1 is drawn from the supplyroll by a holding device 2' mounted on the continuously moving chain 3which is rotated by a large sprocket wheel 19 and two small sprocketwheels and, in this case, a clamp pulling member besides the holdingdevice 2' may be provided. A cutting blade device 7 is mounted on acontinuously moving endless chain 35 parallel with chain 3. This cuttingdevice travels in concert with the chain 3 and cuts off a predeterminedlength of the flat tube 1; then the rear end of the cut tube is sealedby the heat seal member 16. Thereafter, the tube is expanded byspreading the holding device 2 and, at the same time, the open end ofthe tube is turned outwardly and, at this time the pivotally extendablecompasses 30, 31 are inserted therein from a chain 35 running in concertwith the chain 3 of FIG. 4. The end of the heatsealed tube is securelyformed by spreading the compasses and, at the same time, hot air isusually blown into the interior of the bag or tube whereby it issterilized. The extendable compasses are heated usually to 100 C or moreduring their return travel along the rear side 34 of chain 35', this isdesirable for sterilization and also for the forming. The bag whoseforming is completed is held on both sides by bag holders 17 (see FIG.7) and the bag 1 is turned 90 to an erect position by the movement of asector gear 23 connected to said holder and in engagement with a rackgear, and the bag enters a circular travel section of the apparatuswhere fluid or small particle solids in fixed quantity are filled intothe bag from a reservoir tank 4 through the pipe 11. Thereafter, the bagenters a rectilinear travel section of the machine and the open top endof this bag is sealed crosswise at 90 relative to the bottom seal by aheat seal device 15, whereby a sealed tetrahedron l is formed and aguide 14 drops it onto a conveyor (not shown) thereunder.

FIG. 6 shows a detailed mechanism for this holding device 2', namely,rollers 36 having a cellophane tape 37 attached to the circumference ofeach roller with a adhesive coating on the exterior face of the tapes.These cellophane tapes adhere to both surfaces of the flatly folded tube1 when pressed thereagainst as shown in FIG. 7, and tube 1 is expandedup to a predetermined amount by adhesion to the tapes 37 when therollers 36 are retracted and the synthetic resin tube is released fromthe holding device by bearing against a guide plate 38. Further, byutilizing this vertical motion to actuate the pawls 25, against ratchetwheels 24 mounted on pins 28 (shown in FIG. 6) fitted in this holdingdevice 2', namely, when when rollers 36 move vertically relative to eachother, the position of the adhesive surfaces of tapes 37 may be changeddue to the pawls 25, 25' turning rollers 36 to provide fresh adhesivesurfaces. In FIG. 7, a pivoting bag holder 17 and a heat seal device 16are also illustrated.

FIGS. 8 to 10 are supplementary to FIG. 6. FIG. 8 shows the holdingdevice expanding the bag. The closed compasses 30, 31 shown in FIGS. 9,10 are first inserted in the direction of arrow a into the open end ofthe bag; then the compasses are spread in a pivotal movement b toseparate the sides of the bag from its open end to a location adjacentto its sealed end, and thereafter the compasses are closed to theiroriginal position by the pivotal movement 0 and withdrawn from the bagin the direction of arrow d.

FIGS. 11 and 12 show a machine in which the adhesive holding deviceshown in FIG. 6 is used instead of the vacuum holding device of theembodiment of FIGS. 1 to 3.

FIG. 13 illustrates that the filling and sealing of the container by thedevices described hereinbefore is also possible by means of a machineusing circular travel only. FIG. 14 is a schematic showing in which twocircular motion machines are located with a rotary transfer devicearranged therebetween. The feeding, cutting, sealing and expanding ofthe bag take place on the rotary machine at the right side, then thisexpanded bag is fed to the filling machine at the left side through theintermediate rotary transfer device; and when the filling is finished,the open end of the bag is sealed.

FIGS. 15 and 16 show a method employing a rotary machine and two endlesschains on opposite sides thereof. After forming the bag as before, thefilling of the bag is finished at the circular rotary part through thepipe 11 from the reservoir tank 4 rotating around the shaft 38; then theupper part of the bag is sealed to make a tetrahedron by the heat sealmember 15 mounted on the chain 38.

FIG 17 is an elevation showing a filling method suitable for thisinvention.

FIGS. 18 and 19 show a multiple line system in which all of theaforesaid steps are performed in straight and parallel line operationswhich start with fourrolls of flattened seamless tubing 1.

Several advantages can be listed for preferring the adhesive holdingdevice 2' over the vacuum holding device 2.

A. A vacuum source is not necessary.

B. Complicated piping is not necessary.

C. The forming can be securely made by the extendable compasses afterheat sealing. Since the compasses are heated to C or more, they arehygienic. Moreover, since hot air is in the meantime blown in, ahygienic forming is provided.

D. Since the expanding and forming are accomplished by the adhesive tapeon the roller, the mechanism of the machine is very simple and speedy.Besides, a small machine serves the purpose.

E. By mounting the adhesive tape on the roller, the effective area ofthe tape may be moved, so that the number of adhesion operations mayreach ten thousand, as an example, before tape replacement is necessary.

I claim:

l. A method of forming and filling containers comprising the steps ofgripping the leading edge of a continuous flattened seamless tube offlexible synthetic resin thermoplastic material and withdrawing it in ahorizontal plane from a supply station and pulling a section of thematerial of a predetermined length past a cutting station, cutting thesection of predetermined length and completely heat sealing the trailingend of the section while maintaining the gripping engagement with theleading end, continuing the movement of the section in a horizontalplane and while continuing the gripping engagement with the leading endopening the leading end and separating the inside surfaces of thesection, releasing the gripping contact on the section and displacingthe section from the horizontal plane into a vertical orientation withits open leading end facing upwardly and its sealed trailing enddirected downwardly, moving the vertically oriented section into aloading station and filling the section through its open leading endwith a pourable substance, withdrawing the filled section from theloading station and completely heat sealing the leading end of thefilled section so that the sealed leading end lies in a plane extendingtransversely of the plane containing the sealed trailing end of thesection and thereby providing the filled section with a tetrahedralshape.

2. A method as set forth in claim 1, characterized therein by providingan adhesive action for gripping the leading end of the material.

3. A method, as set forth in claim 1, characterized therein by providinga suction action for gripping the leading end of the material.

4. A method, as set forth in claim 1, characterized therein bysterilizing the interior of the cut section after the sealing of itstrailing end and prior to the commencement of the filling step.

1. A method of forming and filling containers comprising the steps ofgripping the leading edge of a continuous flattened seamless tube offlexible synthetic resin thermoplastic material and withdrawing it in ahorizontal plane from a supply station and pulling a section of thematerial of a predetermined length past a cutting station, cutting thesection of predetermined length and completely heat sealing the trailingend of the section while maintaining the gripping engagement with theleading end, continuing the movement of the section in a horizontalplane and while continuing the gripping engagement with the leading endopening the leading end and separating the inside surfaces of thesection, releasing the gripping contact on the section and displacingthe section from the horizontal plane into a vertical orientation withits open leading end facing upwardly and its sealed trailing enddirected downwardly, moving the vertically oriented section into aloading station and filling the section through its open leading endwith a pourable substance, withdrawing the filled section from theloading station and completely heat sealing the leading end of thefilled section so that the sealed leading end lies in a plane extendingtransversely of the plane containing the sealed trailing end of thesection and thereby providing the filled section with a tetrahedralshape.
 2. A method as set forth in claim 1, characterized therein byproviding an adhesive action for gripping the leading end of thematerial.
 3. A method, as set forth in claim 1, characterized therein byproviding a suction action for gripping the leading end of the material.4. A method, as set forth in claim 1, characterized therein bysterilizing the interior of the cut section after the sealing of itstrailing end and prior to the commencement of the filling step.